Forget 31 July 2016 as the alleged start date for the full blown Trump counter intelligence investigation. That day is a sham. The actual campaign to paint Trump as a full fledged stooge of Russia started in early May 2016. We now know the start date thanks to the text messages between star-crossed lovers Strzok and Page and the timeline buried in the Mueller Report:
It is important to understand that the collection of intelligence on U.S. Presidential candidates was not limited to Donald Trump. The collection effort started in the summer of 2015 and included the main Republican candidates and, according to a knowledgeable source, also targeted Bernie Sanders.